1FIA:
reference: Crystal structure of the factor for inversion stimulation FIS at 2.0 A resolution., Kostrewa D, Granzin J, Stock D, Choe HW, Labahn J, Saenger W, J Mol Biol 1992 Jul 5;226(1):209-26. PMID: 1619650

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).